where
\(C_{an\gamma } = 0.011(5) \, e\)  [1]} and
\(\rho _{\rm DM, \, local} \approx 0.4\ \text{GeV}/\text{cm}^3\)  is the local energy density of
axion DM.Note that the local relic density differs from the mean relic density as measured through the CMB and used in Eq:simple ALP relic dansity ratio CMB.
For instance, the axion DM experiment
CASPEr-Electric [2]}, [3]}, [4]}
employs nuclear magnetic resonance techniques to search
for an oscillating nEDM.
Its reach in the \(\lbrace m_a, f_a\rbrace \)  parameter space
is displayed in Fig. REF .
The reach of other techniques
to probe an oscillating nEDM based on
storage rings [5]} are also illustrated there, together with present constraints which exclude \({\cal N}\gtrsim 65\) .
<FIGURE>